Phenol derivatives, phenolic resins, modified

Substituted phenols such as cresols, p-fcrf-butylphenol, / -phcnylphenol, resorcinol, and cardanol (derived from cashew nut shells) have also been used as precursors for phenolic resins. Alkylphenols with at least three carbons in the substituent lead to more hydrophobic phenolic resins that are compatible with many oils, natural resins, and rubbers.7 Such alkylphenolic resins are used as modifying and crosslinking agents for oil varnishes, as coatings and printing inks, and as antioxidants and stabilizers. Bisphenol-A (2,2-p-hydroxyphenylpropane),... 

The CB sheet is coated on the back with microcapsules 5 to 10 pm in diameter, in which leuco dye solution in a nonvolatile solvent is contained. The CF sheet is coated on the front with an acidic coreactant such as reactive clay, zinc salt of salicylic acid derivatives, zinc-modified phenolic resin, etc. On the application of pressure, the microcapsule is ruptured in the area delineated by the pressure pattern, and the leuco dye solution is thereby transferred to the CB sheet to bring about a color-forming reaction with acidic coreactant resulting in a distinct image on the surface of the CF sheet. By inserting a middle sheet (or sheets) called the CFB sheet, which is coated on the front and back with acidic coreactant and microcapsules, respectively, multiple copies can be obtained. 

The CF sheet is prepared by coating an acidic coreactant such as naturally occurring reactive clay, zinc salt of salicylic acid derivatives and zinc modified phenolic resin. 

The substituted phenols and cresols constitute about half the total volume of this group. Para-t-butylphenol is produced by the alkylation of phenol with isobutylene. The principal applications for this derivative are in the manufacture of modified phenolic resins for the rubber industry and in surface coatings. BHT is obtained from isobutylene and p-cresol. Technical-grade BHT is an antioxidant for plastics and elastomers, and is a gum inhibitor in gasoline. Food-grade BHT is an antioxidant in edible oils, preserves, and many other foods. 2,6-Di-t-butylphenol is used to produce a wide range of plastics additives, antioxidants, and gasoline additives. 

Km Kem . [Kenrich Petrochemicals] Cun l phenol derivs. modifier for epoxy, fu and phenolic resins epoxy cure acoeleratm chemical hiteiii -ate. 

One of the more common difficulties in bonding pine veneers and chips is adhesive dryout. Dry-out is associated with the high liquid absorbancy of pine sapwood and it appears especially during long assembly times. This problem can be overcome by using resins modified through reaction with alkylated phenols, especially 3,4-xylenol [52]. Another technique used to achieve similar results is the manipulation of synthesis procedures used in preparing a standard PF resin [52]. The dry-out resistance imparted by alkylated phenols is due to an initial semithermoplastic character in the resin. This is derived from their monomer bifunctionality and the linear polymer that is consequently formed. 

The most important rosin derivatives used in printing ink formulations are rosin oligomers and their esters, metal resinates, modified phenolic and alkyd resins, ester gums, maleic and fumaric acid adducts and their esters. Practically all types of printing inks can be manufactured with rosin-based components, because they provide good miscibility and compatibility with most film formers and other ink additives. 

Rosin modified phenolic resin, another important rosin derivative used in the coating industry, is derived by reacting rosin with a resole type phenolic resin. The extent of modification, the type of phenolic resin used (in terms of the phenolic compound used), and... 

The acid number is mainly defined for rosins and rosin-derived resins and for phenol-modified resins. Standard hydrocarbon resins have zero acid number because the absence of functional groups. However, the acid number allows one to control deterioration by oxidation with formation of carbonyl and carboxyl groups in hydrocarbon resins. Typical acid number values of different resin types are ... 

To expand the diversity of their libraries Brill et al.16 also modified various heterocycles by alkylation, acylation, or metal-mediated coupling reaction prior to resin capture. A remaining chloro substituent was still available for nucleophilic displacement or a palladium-mediated coupling reaction with anilines, phenols, and boronic acids on solid phase [see Fig. 10 for the preparation of purine derivative (62)]. 

Protective coatings are the fourth major user of rosin, either directly or in a modified or derivative form. Varnishes and alkyds are the most common types of protective coatings using rosin. Rosin is combined with a heat-reactive phenol-formaldehyde resin to produce a widely used varnish. Printing inks also use substantial amounts of rosin. 

Choice of the Lignin Modification Reaction. The phenolysis reaction was selected as a means of modifying the structure and reactivity of the ammonium lignin sulfonate for three main practical reasons. First, because this lignin derivative is soluble in (and will ultimately be used in conjunction with) liquid phenol itself second, because unreacted phenol, unlike other reaction solvents, would not have to be removed from the phenolated product after reaction and before conversion to the adhesive resin and third, because lignins and carbohydrates are known to react with phenols under acidic conditions (6,7). 

Resins prepared by Timberlake [1] consisting of benzoguanamine-modified phenol-formaldehyde or melamine-phenol-formaldehyde resins were treated with tris(4-methoxy- phenyl)phosphine oxide to prepare coatings in printed circuit boards. Isomeric mixtures of tris(2-hydroxyphenyl)-phosphine oxide compounds were also converted into resins by Brennan [2] by reacting with tris(4-methoxy-phenyl)phos-phine oxide derivatives. 

Native and microcrystalline cellulose precoated plates are used in the life sciences for the separation of polar compounds (e.g. carbohydrates, carboxylic acids, amino acids, nucleic acid derivatives, phosphates, etc) [85]. These layers are unsuitable for the separation of compounds of low water solubility unless first modified, for example, by acetylation. Several chemically bonded layers have been described for the separation of enantiomers (section 10.5.3). Polyamide and polymeric ion-exchange resins are available in a low performance grade only for the preparation of laboratory-made layers [82]. Polyamide layers are useful for the reversed-phase separation and qualitative analysis of phenols, amino acid derivatives, heterocyclic nitrogen compounds, and carboxylic and sulfonic acids. Ion-exchange layers prepared from poly(ethyleneimine), functionalized poly(styrene-divinylbenzene) and diethylaminoethyl cellulose resins and powders and are used primarily for the separation of inorganic ions and biopolymers. 

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